HMS Belfast - a technical detail

Image: © Chris Allen Taken: 25 Aug 2010

This is one of those important little devices that most people have never heard of and would never give a thought to but it's an absolutely essential device in a ship propelled by a screw. I heard a story about a museum volunteer (not here) who liked to tell visitors that this was a disc brake on the propeller shaft and was used to slow ships down as they would otherwise go faster below the equator!! It is in fact an opened up Michell tilting disc thrust bearing. It is bolted down very firmly to the ship's bottom structure and the thrust generated by the prop is actually transferred to the ship's structure at this point - which in Belfast for this bearing is at the aft end of the forward engine room. The bearing has tilting pads for ahead and astern directions and the pads tilt to allow a wedge shaped oil film to develop between collar and pad and this prevents metal to metal contact. All in all a most amazing device and still an essential part of all modern ships. Our American colleagues call this by a different eponym as the Kingsbury thrust bearing.

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